On Sun, May 25, 2008 at 5:19 PM, Marc Weber
This doesn't work:
$(do a <- reify $ mkName "C" report False $ show a return [] )
Whenever you can avoid using mkName and provide the Name directly using single quotes, in this case ... $(do a <- reify ''C report False $ show a return [] ) ... would do. Note that a preceeding souble single quote is ('') used for type constructors whereas a single quote (') is used for data constructors.
main = print ""
|| [1 of 1] Compiling Main ( test.hs, test.o ) || test.hs|1| `C' is not in scope at a reify
Using mkName "A" results in test.hs|1 error| || DataConI Main.A (ForallT [a_1627391370] [] (AppT (AppT ArrowT (VarT a_1627391370)) (AppT (ConT Main.A) (VarT a_1627391370)))) Main.A (Fixity 9 InfixL) as expected
Why do I need it? I'd like to implement kind of very basic relational data representation the way IxSet is doing it but without dynamics..
It will look like this:
type CDs = Table (Autoinc, Artist, Title, Year) -- col types (Artist, Title, Year) -- keys () -- is detail of type Tracks = Table (Autoinc, Title, RecordingDate) (Title, RecordingDate) (CDs) $(mkDB ["CDs","Tracks"])
To be able to automatically derive insert{CDs,Tracks} delete{CDs,Tracks} update{CDs,Tracks} functions I need to get information about those types.. Is this possible?
Thanks Marc Weber _______________________________________________ template-haskell mailing list template-haskell@haskell.org http://www.haskell.org/mailman/listinfo/template-haskell